3 ZOOM_connection_errcode(c)
4 ZOOM_connection_errmsg(c)
5 ZOOM_connection_addinfo(c)
6 ZOOM_connection_addinfo(c)
7 ZOOM_connection_diagset(c);
9 ZOOM_resultset_record_immediate(s, pos)
10 ZOOM_resultset_cache_reset(r)
11 ZOOM_resultset_sort(r, sort_type, sort_spec)
12 ZOOM_resultset_sort1(r, sort_type, sort_spec)
13 ZOOM_options_set_callback(opt, function, handle)
14 ZOOM_options_create_with_parent2(parent1, parent2)
15 ZOOM_options_getl(opt, name, len)
16 ZOOM_options_setl(opt, name, value, len)
17 ZOOM_options_get_bool(opt, name, defa)
18 ZOOM_options_get_int(opt, name, defa)
19 ZOOM_options_set_int(opt, name, value)
20 ZOOM_connection_scan1(ZOOM_connection c, ZOOM_query startterm)
21 ZOOM_query_cql2rpn(ZOOM_query s, const char *str, ZOOM_connection conn)
23 <chapter id="zoom"><title>ZOOM</title>
25 &zoom; is an acronym for 'Z39.50 Object-Orientation Model' and is
26 an initiative started by Mike Taylor (Mike is from the UK, which
27 explains the peculiar name of the model). The goal of &zoom; is to
28 provide a common Z39.50 client API not bound to a particular
29 programming language or toolkit.
33 From YAZ version 2.1.12, <ulink url="&url.sru;">SRU</ulink> is supported.
34 You can make SRU ZOOM connections by specifying scheme
35 <literal>http://</literal> for the hostname for a connection.
36 The dialect of SRU used is specified by the value of the
37 connection's <literal>sru</literal> option, which may be SRU over
38 HTTP GET (<literal>get</literal>),
39 SRU over HTTP POST (<literal>post</literal>), (SRU over
40 SOAP) (<literal>soap</literal>) or <literal>SOLR</literal>
41 (<ulink url="&url.solr;">SOLR</ulink> Web Service).
42 Using the facility for embedding options in target strings, a
43 connection can be forced to use SRU rather the SRW (the default) by
44 prefixing the target string with <literal>sru=get,</literal>, like this:
45 <literal>sru=get,http://sru.miketaylor.org.uk:80/sru.pl</literal>
48 <ulink url="&url.solr;">SOLR</ulink> protocol support was added to YAZ in version 4.1.0,
49 as a dialect of a SRU protocol, since both are HTTP based protocols.
52 The lack of a simple Z39.50 client API for &yaz; has become more
53 and more apparent over time. So when the first &zoom; specification
55 an implementation for &yaz; was quickly developed. For the first time, it is
56 now as easy (or easier!) to develop clients than servers with &yaz;. This
57 chapter describes the &zoom; C binding. Before going further, please
58 reconsider whether C is the right programming language for the job.
59 There are other language bindings available for &yaz;, and still
61 are in active development. See the
62 <ulink url="&url.zoom;">ZOOM web-site</ulink> for
67 In order to fully understand this chapter you should read and
68 try the example programs <literal>zoomtst1.c</literal>,
69 <literal>zoomtst2.c</literal>, .. in the <literal>zoom</literal>
74 The C language misses features found in object oriented languages
75 such as C++, Java, etc. For example, you'll have to manually,
76 destroy all objects you create, even though you may think of them as
77 temporary. Most objects has a <literal>_create</literal> - and a
78 <literal>_destroy</literal> variant.
79 All objects are in fact pointers to internal stuff, but you don't see
80 that because of typedefs. All destroy methods should gracefully ignore a
81 <literal>NULL</literal> pointer.
84 In each of the sections below you'll find a sub section called
85 protocol behavior, that describes how the API maps to the Z39.50
88 <sect1 id="zoom-connections"><title>Connections</title>
90 <para>The Connection object is a session with a target.
93 #include <yaz/zoom.h>
95 ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
97 ZOOM_connection ZOOM_connection_create (ZOOM_options options);
99 void ZOOM_connection_connect(ZOOM_connection c, const char *host,
101 void ZOOM_connection_destroy(ZOOM_connection c);
104 Connection objects are created with either function
105 <function>ZOOM_connection_new</function> or
106 <function>ZOOM_connection_create</function>.
107 The former creates and automatically attempts to establish a network
108 connection with the target. The latter doesn't establish
109 a connection immediately, thus allowing you to specify options
110 before establishing network connection using the function
111 <function>ZOOM_connection_connect</function>.
112 If the port number, <literal>portnum</literal>, is zero, the
113 <literal>host</literal> is consulted for a port specification.
114 If no port is given, 210 is used. A colon denotes the beginning of
115 a port number in the host string. If the host string includes a
116 slash, the following part specifies a database for the connection.
119 You can prefix the host with a scheme followed by colon. The
120 default scheme is <literal>tcp</literal> (Z39.50 protocol).
121 The scheme <literal>http</literal> selects SRU/get over HTTP by default,
122 but can overridded to use SRU/post, SRW and the SOLR protocol.
125 You can prefix the scheme-qualified host-string with one or more
127 <literal><parameter>key</parameter>=<parameter>value</parameter></literal>
128 sequences, each of which represents an option to be set into the
129 connection structure <emphasis>before</emphasis> the
130 protocol-level connection is forged and the initialization
131 handshake takes place. This facility can be used to provide
132 authentication credentials, as in host-strings such as:
133 <literal>user=admin,password=halfAm4n,tcp:localhost:8017/db</literal>
136 Connection objects should be destroyed using the function
137 <function>ZOOM_connection_destroy</function>.
140 void ZOOM_connection_option_set(ZOOM_connection c,
141 const char *key, const char *val);
143 void ZOOM_connection_option_setl(ZOOM_connection c,
145 const char *val, int len);
147 const char *ZOOM_connection_option_get(ZOOM_connection c,
149 const char *ZOOM_connection_option_getl(ZOOM_connection c,
154 The functions <function>ZOOM_connection_option_set</function> and
155 <function>ZOOM_connection_option_setl</function> allows you to
156 set an option given by <parameter>key</parameter> to the value
157 <parameter>value</parameter> for the connection.
158 For <function>ZOOM_connection_option_set</function>, the
159 value is assumed to be a 0-terminated string. Function
160 <function>ZOOM_connection_option_setl</function> specifies a
161 value of a certain size (len).
164 Functions <function>ZOOM_connection_option_get</function> and
165 <function>ZOOM_connection_option_getl</function> returns
166 the value for an option given by <parameter>key</parameter>.
168 <table id="zoom-connection-options" frame="top">
169 <title>ZOOM Connection Options</title>
171 <colspec colwidth="4*" colname="name"></colspec>
172 <colspec colwidth="7*" colname="description"></colspec>
173 <colspec colwidth="3*" colname="default"></colspec>
176 <entry>Option</entry>
177 <entry>Description</entry>
178 <entry>Default</entry>
183 implementationName</entry><entry>Name of Your client
184 </entry><entry>none</entry></row>
186 user</entry><entry>Authentication user name
187 </entry><entry>none</entry></row>
189 group</entry><entry>Authentication group name
190 </entry><entry>none</entry></row>
192 password</entry><entry>Authentication password.
193 </entry><entry>none</entry></row>
195 host</entry><entry>Target host. This setting is "read-only".
196 It's automatically set internally when connecting to a target.
197 </entry><entry>none</entry></row>
199 proxy</entry><entry>Proxy host. If set, the logical host
200 is encoded in the otherInfo area of the Z39.50 Init PDU
201 with OID 1.2.840.10003.10.1000.81.1.
202 </entry><entry>none</entry></row>
204 clientIP</entry><entry>Client IP. If set, is
205 encoded in the otherInfo area of a Z39.50 PDU with OID
206 1.2.840.10003.10.1000.81.3. Holds the original IP addreses
207 of a client. Is used of ZOOM is used in a gateway of some sort.
208 </entry><entry>none</entry></row>
210 async</entry><entry>If true (1) the connection operates in
211 asynchronous operation which means that all calls are non-blocking
213 <link linkend="zoom.events"><function>ZOOM_event</function></link>.
214 </entry><entry>0</entry></row>
216 maximumRecordSize</entry><entry> Maximum size of single record.
217 </entry><entry>1 MB</entry></row>
219 preferredMessageSize</entry><entry> Maximum size of multiple records.
220 </entry><entry>1 MB</entry></row>
222 lang</entry><entry> Language for negotiation.
223 </entry><entry>none</entry></row>
225 charset</entry><entry> Character set for negotiation.
226 </entry><entry>none</entry></row>
228 serverImplementationId</entry><entry>
229 Implementation ID of server. (The old targetImplementationId
230 option is also supported for the benefit of old applications.)
231 </entry><entry>none</entry></row>
233 targetImplementationName</entry><entry>
234 Implementation Name of server. (The old
235 targetImplementationName option is also supported for the
236 benefit of old applications.)
237 </entry><entry>none</entry></row>
239 serverImplementationVersion</entry><entry>
240 Implementation Version of server. (the old
241 targetImplementationVersion option is also supported for the
242 benefit of old applications.)
243 </entry><entry>none</entry></row>
245 databaseName</entry><entry>One or more database names
246 separated by character plus (<literal>+</literal>), which to
247 be used by subsequent search requests on this Connection.
248 </entry><entry>Default</entry></row>
250 piggyback</entry><entry>True (1) if piggyback should be
251 used in searches; false (0) if not.
252 </entry><entry>1</entry></row>
254 smallSetUpperBound</entry><entry>If hits is less than or equal to this
255 value, then target will return all records using small element set name
256 </entry><entry>0</entry></row>
258 largeSetLowerBound</entry><entry>If hits is greater than this
259 value, the target will return no records.
260 </entry><entry>1</entry></row>
262 mediumSetPresentNumber</entry><entry>This value represents
263 the number of records to be returned as part of a search when when
264 hits is less than or equal to large set lower bound and if hits
265 is greater than small set upper bound.
266 </entry><entry>0</entry></row>
268 smallSetElementSetName</entry><entry>
269 The element set name to be used for small result sets.
270 </entry><entry>none</entry></row>
272 mediumSetElementSetName</entry><entry>
273 The element set name to be for medium-sized result sets.
274 </entry><entry>none</entry></row>
276 init_opt_search, init_opt_present, init_opt_delSet, etc.</entry><entry>
277 After a successful Init, these options may be interrogated to
278 discover whether the server claims to support the specified
280 </entry><entry>none</entry></row>
282 <entry>sru</entry><entry>
283 SRU/SOLR transport type. Must be either <literal>soap</literal>,
284 <literal>get</literal>, <literal>post</literal>, or
285 <literal>solr</literal>.
286 </entry><entry>soap</entry></row>
288 sru_version</entry><entry>
289 SRU/SRW version. Should be <literal>1.1</literal>, or
290 <literal>1.2</literal>. This is , prior to connect, the version
291 to offer (highest version). And following connect (in fact
292 first operation), holds the negotiated version with the server
293 (same or lower version).
294 </entry><entry>1.2</entry></row>
296 facets</entry><entry>
297 A FacetList is comma-separated list of facet, which is defined
298 as <literal>AttributeList</literal> and a optional FacetTerm
299 (a Term and a frequency). On request the terms is missing.
300 On response the the list contains the terms that the target
302 </entry><entry>none</entry></row>
304 apdulog</entry><entry>
305 If set to a true value such as "1", a log of low-level
306 protocol packets is emitted on standard error stream. This
307 can be very useful for debugging.
308 </entry><entry>0</entry></row>
310 saveAPDU</entry><entry>
311 If set to a true value such as "1", a log of low-level
312 protocol packets is saved. The log can be retrieved by reading
313 option APDU. Setting saveAPDU always has the side effect of
314 resetting the currently saved log. This setting is
315 <emphasis>write-only</emphasis>. If read, NULL will be returned.
316 It is only recognized in
317 <function>ZOOM_connection_option_set</function>.
318 </entry><entry>0</entry></row>
321 Returns the log of protocol packets. Will be empty if logging
322 is not enabled (see saveAPDU above). This setting is
323 <emphasis>read-only</emphasis>. It is only recognized if used
324 in call to <function>ZOOM_connection_option_get</function> or
325 <function>ZOOM_connection_option_getl</function>.
326 </entry><entry></entry></row>
331 If either option <literal>lang</literal> or <literal>charset</literal>
333 <ulink url="&url.z39.50.charneg;">
334 Character Set and Language Negotiation</ulink> is in effect.
337 int ZOOM_connection_error(ZOOM_connection c, const char **cp,
338 const char **addinfo);
339 int ZOOM_connection_error_x(ZOOM_connection c, const char **cp,
340 const char **addinfo, const char **dset);
343 Function <function>ZOOM_connection_error</function> checks for
344 errors for the last operation(s) performed. The function returns
345 zero if no errors occurred; non-zero otherwise indicating the error.
346 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
347 holds messages for the error and additional-info if passed as
348 non-<literal>NULL</literal>. Function
349 <function>ZOOM_connection_error_x</function> is an extended version
350 of <function>ZOOM_connection_error</function> that is capable of
351 returning name of diagnostic set in <parameter>dset</parameter>.
353 <sect2 id="zoom-connection-z39.50">
354 <title>Z39.50 Protocol behavior</title>
356 The calls <function>ZOOM_connection_new</function> and
357 <function>ZOOM_connection_connect</function> establishes a TCP/IP
358 connection and sends an Initialize Request to the target if
359 possible. In addition, the calls waits for an Initialize Response
360 from the target and the result is inspected (OK or rejected).
363 If <literal>proxy</literal> is set then the client will establish
364 a TCP/IP connection with the peer as specified by the
365 <literal>proxy</literal> host and the hostname as part of the
366 connect calls will be set as part of the Initialize Request.
367 The proxy server will then "forward" the PDU's transparently
368 to the target behind the proxy.
371 For the authentication parameters, if option <literal>user</literal>
372 is set and both options <literal>group</literal> and
373 <literal>pass</literal> are unset, then Open style
374 authentication is used (Version 2/3) in which case the username
375 is usually followed by a slash, then by a password.
376 If either <literal>group</literal>
377 or <literal>pass</literal> is set then idPass authentication
378 (Version 3 only) is used. If none of the options are set, no
379 authentication parameters are set as part of the Initialize Request
383 When option <literal>async</literal> is 1, it really means that
384 all network operations are postponed (and queued) until the
385 function <literal>ZOOM_event</literal> is invoked. When doing so
386 it doesn't make sense to check for errors after
387 <literal>ZOOM_connection_new</literal> is called since that
388 operation "connecting - and init" is still incomplete and the
389 API cannot tell the outcome (yet).
392 <sect2 id="zoom.sru.init.behavior">
393 <title>SRU/SOLR Protocol behavior</title>
395 The HTTP based protocols (SRU, SRW, SOLR) doesn't feature an Inititialize Request, so
396 the connection phase merely establishes a TCP/IP connection
397 with the SOAP service.
399 <para>Most of the ZOOM connection options do not
400 affect SRU/SOLR and they are ignored. However, future versions
401 of &yaz; might honor <literal>implementationName</literal> and
402 put that as part of User-Agent header for HTTP requests.
405 The <literal>charset</literal> is used in the Content-Type header
410 <sect1 id="zoom.query"><title>Queries</title>
412 Query objects represents queries.
415 ZOOM_query ZOOM_query_create(void);
417 void ZOOM_query_destroy(ZOOM_query q);
419 int ZOOM_query_prefix(ZOOM_query q, const char *str);
421 int ZOOM_query_cql(ZOOM_query s, const char *str);
423 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
426 Create query objects using <function>ZOOM_query_create</function>
427 and destroy them by calling <function>ZOOM_query_destroy</function>.
428 RPN-queries can be specified in <link linkend="PQF">PQF</link>
429 notation by using the
430 function <function>ZOOM_query_prefix</function>.
431 The <function>ZOOM_query_cql</function> specifies a CQL
432 query to be sent to the server/target.
433 More query types will be added in future versions of &yaz;, such as
434 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
435 etc. In addition to a search, a sort criteria may be set. Function
436 <function>ZOOM_query_sortby</function> specifies a
437 sort criteria using the same string notation for sort as offered by
438 the <link linkend="sortspec">YAZ client</link>.
440 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
442 The query object is just an interface for the member Query
443 in the SearchRequest. The sortby-function is an interface to the
444 sortSequence member of the SortRequest.
448 <sect1 id="zoom.resultsets"><title>Result sets</title>
450 The result set object is a container for records returned from
454 ZOOM_resultset ZOOM_connection_search(ZOOM_connection, ZOOM_query q);
456 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
458 void ZOOM_resultset_destroy(ZOOM_resultset r);
461 Function <function>ZOOM_connection_search</function> creates
462 a result set given a connection and query.
463 Destroy a result set by calling
464 <function>ZOOM_resultset_destroy</function>.
465 Simple clients may using PQF only may use function
466 <function>ZOOM_connection_search_pqf</function> in which case
467 creating query objects is not necessary.
470 void ZOOM_resultset_option_set(ZOOM_resultset r,
471 const char *key, const char *val);
473 const char *ZOOM_resultset_option_get(ZOOM_resultset r, const char *key);
475 size_t ZOOM_resultset_size(ZOOM_resultset r);
478 Functions <function>ZOOM_resultset_options_set</function> and
479 <function>ZOOM_resultset_get</function> sets and gets an option
480 for a result set similar to <function>ZOOM_connection_option_get</function>
481 and <function>ZOOM_connection_option_set</function>.
484 The number of hits also called result-count is returned by
485 function <function>ZOOM_resultset_size</function>.
487 <table id="zoom.resultset.options"
488 frame="top"><title>ZOOM Result set Options</title>
490 <colspec colwidth="4*" colname="name"></colspec>
491 <colspec colwidth="7*" colname="description"></colspec>
492 <colspec colwidth="2*" colname="default"></colspec>
495 <entry>Option</entry>
496 <entry>Description</entry>
497 <entry>Default</entry>
502 start</entry><entry>Offset of first record to be
503 retrieved from target. First record has offset 0 unlike the
504 protocol specifications where first record has position 1.
505 This option affects ZOOM_resultset_search and
506 ZOOM_resultset_search_pqf and must be set before any of
507 these functions are invoked. If a range of
508 records must be fetched manually after search,
509 function ZOOM_resultset_records should be used.
510 </entry><entry>0</entry></row>
512 count</entry><entry>Number of records to be retrieved.
513 This option affects ZOOM_resultset_search and
514 ZOOM_resultset_search_pqf and must be set before any of
515 these functions are invoked.
516 </entry><entry>0</entry></row>
518 presentChunk</entry><entry>The number of records to be
519 requested from the server in each chunk (present request). The
520 value 0 means to request all the records in a single chunk.
521 (The old <literal>step</literal>
522 option is also supported for the benefit of old applications.)
523 </entry><entry>0</entry></row>
525 elementSetName</entry><entry>Element-Set name of records.
526 Most targets should honor element set name <literal>B</literal>
527 and <literal>F</literal> for brief and full respectively.
528 </entry><entry>none</entry></row>
530 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
531 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
532 </entry><entry>none</entry></row>
534 schema</entry><entry>Schema for retrieval, such as
535 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
536 </entry><entry>none</entry></row>
538 setname</entry><entry>Name of Result Set (Result Set ID).
539 If this option isn't set, the ZOOM module will automatically
540 allocate a result set name.
541 </entry><entry>default</entry></row>
543 rpnCharset</entry><entry>Character set for RPN terms.
544 If this is set, ZOOM C will assume that the ZOOM application is
545 running UTF-8. Terms in RPN queries are then converted to the
546 rpnCharset. If this is unset, ZOOM C will not assume any encoding
547 of RPN terms and no conversion is performed.
548 </entry><entry>none</entry></row>
553 For servers that support Search Info report, the following
554 options may be read using <function>ZOOM_resultset_get</function>.
555 This detailed information is read after a successful search has
559 This information is a list of of items, where each item is
560 information about a term or subquery. All items in the list
562 <literal>SearchResult.</literal><replaceable>no</replaceable>
563 where no presents the item number (0=first, 1=second).
564 Read <literal>searchresult.size</literal> to determine the
567 <table id="zoom.search.info.report.options"
568 frame="top"><title>Search Info Report Options</title>
570 <colspec colwidth="4*" colname="name"></colspec>
571 <colspec colwidth="7*" colname="description"></colspec>
574 <entry>Option</entry>
575 <entry>Description</entry>
580 <entry>searchresult.size</entry>
582 number of search result entries. This option is-nonexistant
583 if no entries are returned by the server.
587 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
588 <entry>sub query ID</entry>
591 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
592 <entry>result count for item (number of hits)</entry>
595 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
596 <entry>subquery term</entry>
600 searchresult.<replaceable>no</replaceable>.interpretation.term
602 <entry>interpretation term</entry>
606 searchresult.<replaceable>no</replaceable>.recommendation.term
608 <entry>recommendation term</entry>
613 <sect2 id="zoom.z3950.resultset.behavior">
614 <title>Z39.50 Protocol behavior</title>
616 The creation of a result set involves at least a SearchRequest
617 - SearchResponse protocol handshake. Following that, if a sort
618 criteria was specified as part of the query, a SortRequest -
619 SortResponse handshake takes place. Note that it is necessary to
620 perform sorting before any retrieval takes place, so no records will
621 be returned from the target as part of the SearchResponse because these
622 would be unsorted. Hence, piggyback is disabled when sort criteria
623 are set. Following Search - and a possible sort - Retrieval takes
624 place - as one or more Present Requests/Response pairs being
628 The API allows for two different modes for retrieval. A high level
629 mode which is somewhat more powerful and a low level one.
630 The low level is enabled when searching on a Connection object
631 for which the settings
632 <literal>smallSetUpperBound</literal>,
633 <literal>mediumSetPresentNumber</literal> and
634 <literal>largeSetLowerBound</literal> are set. The low level mode
635 thus allows you to precisely set how records are returned as part
636 of a search response as offered by the Z39.50 protocol.
637 Since the client may be retrieving records as part of the
638 search response, this mode doesn't work well if sorting is used.
641 The high-level mode allows you to fetch a range of records from
642 the result set with a given start offset. When you use this mode
643 the client will automatically use piggyback if that is possible
644 with the target and perform one or more present requests as needed.
645 Even if the target returns fewer records as part of a present response
646 because of a record size limit, etc. the client will repeat sending
647 present requests. As an example, if option <literal>start</literal>
648 is 0 (default) and <literal>count</literal> is 4, and
649 <literal>piggyback</literal> is 1 (default) and no sorting criteria
650 is specified, then the client will attempt to retrieve the 4
651 records as part the search response (using piggyback). On the other
652 hand, if either <literal>start</literal> is positive or if
653 a sorting criteria is set, or if <literal>piggyback</literal>
654 is 0, then the client will not perform piggyback but send Present
658 If either of the options <literal>mediumSetElementSetName</literal> and
659 <literal>smallSetElementSetName</literal> are unset, the value
660 of option <literal>elementSetName</literal> is used for piggyback
661 searches. This means that for the high-level mode you only have
662 to specify one elementSetName option rather than three.
665 <sect2 id="zoom.sru.resultset.behavior">
666 <title>SRU Protocol behavior</title>
668 Current version of &yaz; does not take advantage of a result set id
669 returned by the SRU server. Future versions might do, however.
670 Since, the ZOOM driver does not save result set IDs any
671 present (retrieval) is transformed to a SRU SearchRetrieveRequest
672 with same query but, possibly, different offsets.
675 Option <literal>schema</literal> specifies SRU schema
676 for retrieval. However, options <literal>elementSetName</literal> and
677 <literal>preferredRecordSyntax</literal> are ignored.
680 Options <literal>start</literal> and <literal>count</literal>
681 are supported by SRU.
682 The remaining options
683 <literal>piggyback</literal>,
684 <literal>smallSetUpperBound</literal>,
685 <literal>largeSetLowerBound</literal>,
686 <literal>mediumSetPresentNumber</literal>,
687 <literal>mediumSetElementSetName</literal>,
688 <literal>smallSetElementSetName</literal> are
692 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
693 If PQF is used, however, the PQF query is transferred anyway
694 using non-standard element <literal>pQuery</literal> in
695 SRU SearchRetrieveRequest.
698 SOLR queries has to be done in SOLR query format.
701 Unfortunately, SRU or SOLR does not define a database setting. Hence,
702 <literal>databaseName</literal> is unsupported and ignored.
703 However, the path part in host parameter for functions
704 <function>ZOOM_connecton_new</function> and
705 <function>ZOOM_connection_connect</function> acts as a
706 database (at least for the &yaz; SRU server).
710 <sect1 id="zoom.records"><title>Records</title>
712 A record object is a retrieval record on the client side -
713 created from result sets.
716 void ZOOM_resultset_records(ZOOM_resultset r,
718 size_t start, size_t count);
719 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
721 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
724 int ZOOM_record_error(ZOOM_record rec, const char **msg,
725 const char **addinfo, const char **diagset);
727 ZOOM_record ZOOM_record_clone(ZOOM_record rec);
729 void ZOOM_record_destroy(ZOOM_record rec);
732 References to temporary records are returned by functions
733 <function>ZOOM_resultset_records</function> or
734 <function>ZOOM_resultset_record</function>.
737 If a persistent reference to a record is desired
738 <function>ZOOM_record_clone</function> should be used.
739 It returns a record reference that should be destroyed
740 by a call to <function>ZOOM_record_destroy</function>.
743 A single record is returned by function
744 <function>ZOOM_resultset_record</function> that takes a
745 position as argument. First record has position zero.
746 If no record could be obtained <literal>NULL</literal> is returned.
749 Error information for a record can be checked with
750 <function>ZOOM_record_error</function> which returns non-zero
751 (error code) if record is in error, called <emphasis>Surrogate
752 Diagnostics</emphasis> in Z39.50.
755 Function <function>ZOOM_resultset_records</function> retrieves
756 a number of records from a result set. Parameter <literal>start</literal>
757 and <literal>count</literal> specifies the range of records to
758 be returned. Upon completion array
759 <literal>recs[0], ..recs[count-1]</literal>
760 holds record objects for the records. The array of records
761 <literal>recs</literal> should be allocated prior the call
762 <function>ZOOM_resultset_records</function>. Note that for those
763 records that couldn't be retrieved from the target
764 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
766 <para id="zoom.record.get">
767 In order to extract information about a single record,
768 <function>ZOOM_record_get</function> is provided. The
769 function returns a pointer to certain record information. The
770 nature (type) of the pointer depends on the parameter,
771 <parameter>type</parameter>.
774 The <parameter>type</parameter> is a string of the format:
777 <replaceable>format</replaceable>[;charset=<replaceable>from</replaceable>[/<replaceable>opacfrom</replaceable>][,<replaceable>to</replaceable>]][;format=<replaceable>v</replaceable>]
780 where <replaceable>format</replaceable> specifies the format of the
781 returned record, <replaceable>from</replaceable>
782 specifies the character set of the record in its original form
783 (as returned by the server), <replaceable>to</replaceable> specifies
784 the output (returned)
785 character set encoding.
786 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
787 If charset is not given, then no character set conversion takes place.
790 <para>OPAC records may be returned in a different
791 set from the bibliographic MARC record. If this is this the case,
792 <replaceable>opacfrom</replaceable> should be set to the character set
793 of the OPAC record part.
797 Specifying the OPAC record character set requires YAZ 4.1.5 or later.
801 The format argument controls whether record data should be XML
802 pretty-printed (post process operation).
803 It is enabled only if format value <replaceable>v</replaceable> is
804 <literal>1</literal> and the record content is XML well-formed.
807 In addition, for certain types, the length
808 <literal>len</literal> passed will be set to the size in bytes of
809 the returned information.
812 The following are the supported values for <replaceable>form</replaceable>.
814 <varlistentry><term><literal>database</literal></term>
815 <listitem><para>Database of record is returned
816 as a C null-terminated string. Return type
817 <literal>const char *</literal>.
820 <varlistentry><term><literal>syntax</literal></term>
821 <listitem><para>The transfer syntax of the record is returned
822 as a C null-terminated string containing the symbolic name of
823 the record syntax, e.g. <literal>Usmarc</literal>. Return type
825 <literal>const char *</literal>.
828 <varlistentry><term><literal>schema</literal></term>
829 <listitem><para>The schema of the record is returned
830 as a C null-terminated string. Return type is
831 <literal>const char *</literal>.
834 <varlistentry><term><literal>render</literal></term>
835 <listitem><para>The record is returned in a display friendly
836 format. Upon completion buffer is returned
837 (type <literal>const char *</literal>) and length is stored in
838 <literal>*len</literal>.
841 <varlistentry><term><literal>raw</literal></term>
842 <listitem><para>The record is returned in the internal
843 YAZ specific format. For GRS-1, Explain, and others, the
844 raw data is returned as type
845 <literal>Z_External *</literal> which is just the type for
846 the member <literal>retrievalRecord</literal> in
847 type <literal>NamePlusRecord</literal>.
848 For SUTRS and octet aligned record (including all MARCs) the
849 octet buffer is returned and the length of the buffer.
852 <varlistentry><term><literal>xml</literal></term>
853 <listitem><para>The record is returned in XML if possible.
854 SRU, SOLR and Z39.50 records with transfer syntax XML are
855 returned verbatim. MARC records are returned in
856 <ulink url="&url.marcxml;">
859 (converted from ISO2709 to MARCXML by YAZ).
860 OPAC records are also converted to XML and the
861 bibliographic record is converted to MARCXML (when possible).
862 GRS-1 records are not supported for this form.
863 Upon completion, the XML buffer is returned
864 (type <literal>const char *</literal>) and length is stored in
865 <literal>*len</literal>.
868 <varlistentry><term><literal>opac</literal></term>
869 <listitem><para>OPAC information for record is returned in XML
870 if an OPAC record is present at the position given. If no
871 OPAC record is present, a NULL pointer is returned.
874 <varlistentry><term><literal>txml</literal></term>
875 <listitem><para>The record is returned in TurboMARC if possible.
876 SRU and Z39.50 records with transfer syntax XML are
877 returned verbatim. MARC records are returned in
878 <link linkend="tools.turbomarc">
881 (converted from ISO2709 to TurboMARC by YAZ).
882 Upon completion, the XML buffer is returned
883 (type <literal>const char *</literal>) and length is stored in
884 <literal>*len</literal>.
891 <ulink url="&url.marc21;">MARC21</ulink>
893 <ulink url="&url.marc8;">MARC-8</ulink>
894 character set encoding.
895 An application that wishes to display in Latin-1 would use
897 render; charset=marc8,iso-8859-1
900 <sect2 id="zoom.z3950.record.behavior">
901 <title>Z39.50 Protocol behavior</title>
903 The functions <function>ZOOM_resultset_record</function> and
904 <function>ZOOM_resultset_records</function> inspects the client-side
905 record cache. Records not found in cache are fetched using
907 The functions may block (and perform network I/O) - even though option
908 <literal>async</literal> is 1, because they return records objects.
909 (and there's no way to return records objects without retrieving them!).
912 There is a trick, however, in the usage of function
913 <function>ZOOM_resultset_records</function> that allows for
914 delayed retrieval (and makes it non-blocking). By using
915 a null pointer for <parameter>recs</parameter> you're indicating
916 you're not interested in getting records objects
917 <emphasis>now</emphasis>.
920 <sect2 id="zoom.sru.record.behavior">
921 <title>SRU/SOLR Protocol behavior</title>
923 The ZOOM driver for SRU/SOLR treats records returned by a SRU/SOLR server
924 as if they where Z39.50 records with transfer syntax XML and
925 no element set name or database name.
929 <sect1 id="zoom.facets"><title>Facets</title>
931 Facets operations is not part of the official ZOOM specification, but is an Index Data extension
932 for YAZ-based Z39.50 targets or <ulink url="&url.solr;">SOLR</ulink> targets.
933 In case the target can and is requested to return facets, using a result set the ZOOM client
934 can request one or all facet fields. Using a facet field the client can request the term count and
935 then interate over the terms.
938 ZOOM_facet_field *ZOOM_resultset_facets(ZOOM_resultset r);
939 const char ** ZOOM_resultset_facets_names(ZOOM_resultset r);
940 ZOOM_facet_field ZOOM_resultset_get_facet_field(ZOOM_resultset r, const char *facet_name);
941 ZOOM_facet_field ZOOM_resultset_get_facet_field_by_index(ZOOM_resultset r, int pos);
942 size_t ZOOM_resultset_facets_size(ZOOM_resultset r);
944 const char *ZOOM_facet_field_name(ZOOM_facet_field facet_field);
945 size_t ZOOM_facet_field_term_count(ZOOM_facet_field facet_field);
946 const char *ZOOM_facet_field_get_term(ZOOM_facet_field facet_field, size_t idx, int *freq);
949 References to temporary structures are returned by all functions. They are only valid as long the Result set is valid.
950 <function>ZOOM_resultset_get_facet_field</function> or
951 <function>ZOOM_resultset_get_facet_field_by_index</function>.
952 <function>ZOOM_resultset_facets</function>.
953 <function>ZOOM_resultset_facets_names</function>.
954 <function>ZOOM_facet_field_name</function>.
955 <function>ZOOM_facet_field_get_term</function>.
957 <para id="zoom.resultset.get_facet_field">
958 A single Facet field is returned by function
959 <function>ZOOM_resultset_get_facet_field</function> or <function>ZOOM_resultset_get_facet_field_by_index</function> that takes a
960 result set and facet name or positive index respectively. First facet has position zero.
961 If no facet could be obtained (invalid name or index out of bounds) <literal>NULL</literal> is returned.
963 <para id="zoom.resultset.facets">
964 An array of facets field can be returned by <function>ZOOM_resultset_facets</function>. The length of the array is
965 given by <function>ZOOM_resultset_facets_size</function>. The array is zero-based and last entry will be at
966 <function>ZOOM_resultset_facets_size(result_set)</function>-1.
968 <para id="zoom.resultset.facets_names">
969 It is possible to interate over facets by name, by calling <function>ZOOM_resultset_facets_names</function>.
970 This will return an const array of char * where each string can be used as parameter for
971 <function>ZOOM_resultset_get_facet_field</function>.
974 Function <function>ZOOM_facet_field_name</function> gets the request facet name from a returned facet field.
977 Function <function>ZOOM_facet_field_get_term</function> returns the idx'th term and term count for a facet field.
978 Idx must between 0 and <function>ZOOM_facet_field_term_count</function>-1, otherwise the returned reference will be
979 <literal>NULL</literal>. On a valid idx, the value of the freq reference will be the term count.
980 The *freq parameter must be valid pointer to integer.
983 <sect1 id="zoom.scan"><title>Scan</title>
985 This section describes an interface for Scan. Scan is not an
986 official part of the ZOOM model yet. The result of a scan operation
987 is the <literal>ZOOM_scanset</literal> which is a set of terms
988 returned by a target.
992 The Scan interface is supported for both Z39.50, SRU (and SOLR?).
996 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
997 const char *startpqf);
999 ZOOM_scanset ZOOM_connection_scan1(ZOOM_connection c,
1002 size_t ZOOM_scanset_size(ZOOM_scanset scan);
1004 const char *ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
1005 size_t *occ, size_t *len);
1007 const char *ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
1008 size_t *occ, size_t *len);
1010 void ZOOM_scanset_destroy(ZOOM_scanset scan);
1012 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
1015 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
1019 The scan set is created by function
1020 <function>ZOOM_connection_scan</function> which performs a scan
1021 operation on the connection using the specified
1022 <parameter>startpqf</parameter>.
1023 If the operation was successful, the size of the scan set can be
1024 retrieved by a call to <function>ZOOM_scanset_size</function>.
1025 Like result sets, the items are numbered 0,..size-1.
1026 To obtain information about a particular scan term, call function
1027 <function>ZOOM_scanset_term</function>. This function takes
1028 a scan set offset <literal>pos</literal> and returns a pointer
1029 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
1031 If present, the <literal>occ</literal> and <literal>len</literal>
1032 are set to the number of occurrences and the length
1033 of the actual term respectively.
1034 <function>ZOOM_scanset_display_term</function> is similar to
1035 <function>ZOOM_scanset_term</function> except that it returns
1036 the <emphasis>display term</emphasis> rather than the raw term.
1037 In a few cases, the term is different from display term. Always
1038 use the display term for display and the raw term for subsequent
1039 scan operations (to get more terms, next scan result, etc).
1042 A scan set may be freed by a call to function
1043 <function>ZOOM_scanset_destroy</function>.
1044 Functions <function>ZOOM_scanset_option_get</function> and
1045 <function>ZOOM_scanset_option_set</function> retrieves and sets
1046 an option respectively.
1050 The <parameter>startpqf</parameter> is a subset of PQF, namely
1051 the Attributes+Term part. Multiple <literal>@attr</literal> can
1052 be used. For example to scan in title (complete) phrases:
1054 @attr 1=4 @attr 6=2 "science o"
1059 The <function>ZOOM_connecton_scan1</function> is a newer and
1060 more generic alternative to <function>ZOOM_connection_scan</function>
1061 which allows to use both CQL and PQF for Scan.
1064 <table frame="top" id="zoom.scanset.options">
1065 <title>ZOOM Scan Set Options</title>
1067 <colspec colwidth="4*" colname="name"></colspec>
1068 <colspec colwidth="7*" colname="description"></colspec>
1069 <colspec colwidth="2*" colname="default"></colspec>
1072 <entry>Option</entry>
1073 <entry>Description</entry>
1074 <entry>Default</entry>
1079 number</entry><entry>Number of Scan Terms requested in next scan.
1080 After scan it holds the actual number of terms returned.
1081 </entry><entry>20</entry></row>
1083 position</entry><entry>Preferred Position of term in response
1084 in next scan; actual position after completion of scan.
1085 </entry><entry>1</entry></row>
1087 stepSize</entry><entry>Step Size
1088 </entry><entry>0</entry></row>
1090 scanStatus</entry><entry>An integer indicating the Scan Status
1092 </entry><entry>0</entry></row>
1094 rpnCharset</entry><entry>Character set for RPN terms.
1095 If this is set, ZOOM C will assume that the ZOOM application is
1096 running UTF-8. Terms in RPN queries are then converted to the
1097 rpnCharset. If this is unset, ZOOM C will not assume any encoding
1098 of RPN terms and no conversion is performed.
1099 </entry><entry>none</entry></row>
1105 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
1107 ZOOM offers an interface to a subset of the Z39.50 extended services
1108 as well as a few privately defined ones:
1113 Z39.50 Item Order (ILL).
1114 See <xref linkend="zoom.item.order"/>.
1119 Record Update. This allows a client to insert, modify or delete
1121 See <xref linkend="zoom.record.update"/>.
1126 Database Create. This a non-standard feature. Allows a client
1127 to create a database.
1128 See <xref linkend="zoom.database.create"/>.
1133 Database Drop. This a non-standard feature. Allows a client
1134 to delete/drop a database.
1135 See <xref linkend="zoom.database.drop"/>.
1140 Commit operation. This a non-standard feature. Allows a client
1141 to commit operations.
1142 See <xref linkend="zoom.commit"/>.
1145 <!-- all the ILL PDU options should go here too -->
1148 To create an extended service operation a <literal>ZOOM_package</literal>
1149 must be created. The operation is a five step operation. The
1150 package is created, package is configured by means of options,
1151 the package is send, result is inspected (by means of options),
1152 the package is destroyed.
1155 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
1156 ZOOM_options options);
1158 const char *ZOOM_package_option_get(ZOOM_package p,
1160 void ZOOM_package_option_set(ZOOM_package p, const char *key,
1162 void ZOOM_package_send(ZOOM_package p, const char *type);
1164 void ZOOM_package_destroy(ZOOM_package p);
1167 The <function>ZOOM_connection_package</function> creates a
1168 package for the connection given using the options specified.
1171 Functions <function>ZOOM_package_option_get</function> and
1172 <function>ZOOM_package_option_set</function> gets and sets
1176 <function>ZOOM_package_send</function> sends
1177 the package the via connection specified in
1178 <function>ZOOM_connection_package</function>.
1179 The <parameter>type</parameter> specifies the actual extended service
1180 package type to be sent.
1183 <table frame="top" id="zoom.extendedservices.options">
1184 <title>Extended Service Common Options</title>
1186 <colspec colwidth="4*" colname="name"></colspec>
1187 <colspec colwidth="7*" colname="description"></colspec>
1188 <colspec colwidth="3*" colname="default"></colspec>
1191 <entry>Option</entry>
1192 <entry>Description</entry>
1193 <entry>Default</entry>
1198 <entry>package-name</entry>
1199 <entry>Extended Service Request package name. Must be specified
1200 as part of a request</entry>
1204 <entry>user-id</entry>
1205 <entry>User ID of Extended Service Package. Is a request option</entry>
1209 <entry>function</entry>
1211 Function of package - one of <literal>create</literal>,
1212 <literal>delete</literal>, <literal>modify</literal>. Is
1215 <entry><literal>create</literal></entry>
1218 <entry>waitAction</entry>
1220 Wait action for package. Possible values:
1221 <literal>wait</literal>, <literal>waitIfPossible</literal>,
1222 <literal>dontWait</literal> or <literal>dontReturnPackage</literal>.
1224 <entry><literal>waitIfPossible</literal></entry>
1227 <entry>targetReference</entry>
1229 Target Reference. This is part of the response as returned
1230 by the server. Read it after a successful operation.
1232 <entry><literal>none</literal></entry>
1238 <sect2 id="zoom.item.order"><title>Item Order</title>
1240 For Item Order, type must be set to <literal>itemorder</literal> in
1241 <function>ZOOM_package_send</function>.
1244 <table frame="top" id="zoom.item.order.options">
1245 <title>Item Order Options</title>
1247 <colspec colwidth="4*" colname="name"></colspec>
1248 <colspec colwidth="7*" colname="description"></colspec>
1249 <colspec colwidth="3*" colname="default"></colspec>
1252 <entry>Option</entry>
1253 <entry>Description</entry>
1254 <entry>Default</entry>
1259 <entry>contact-name</entry>
1260 <entry>ILL contact name</entry>
1264 <entry>contact-phone</entry>
1265 <entry>ILL contact phone</entry>
1269 <entry>contact-email</entry>
1270 <entry>ILL contact email</entry>
1274 <entry>itemorder-item</entry>
1275 <entry>Position for item (record) requested. An integer</entry>
1284 <sect2 id="zoom.record.update"><title>Record Update</title>
1286 For Record Update, type must be set to <literal>update</literal> in
1287 <function>ZOOM_package_send</function>.
1290 <table frame="top" id="zoom.record.update.options">
1291 <title>Record Update Options</title>
1293 <colspec colwidth="4*" colname="name"></colspec>
1294 <colspec colwidth="7*" colname="description"></colspec>
1295 <colspec colwidth="3*" colname="default"></colspec>
1298 <entry>Option</entry>
1299 <entry>Description</entry>
1300 <entry>Default</entry>
1305 <entry>action</entry>
1307 The update action. One of
1308 <literal>specialUpdate</literal>,
1309 <literal>recordInsert</literal>,
1310 <literal>recordReplace</literal>,
1311 <literal>recordDelete</literal>,
1312 <literal>elementUpdate</literal>.
1314 <entry><literal>specialUpdate (recordInsert for updateVersion=1 which does not support specialUpdate)</literal></entry>
1317 <entry>recordIdOpaque</entry>
1318 <entry>Opaque Record ID</entry>
1322 <entry>recordIdNumber</entry>
1323 <entry>Record ID number</entry>
1327 <entry>record</entry>
1328 <entry>The record itself</entry>
1332 <entry>recordOpaque</entry>
1333 <entry>Specifies an opaque record which is
1334 encoded as an ASN.1 ANY type with the OID as tiven by option
1335 <literal>syntax</literal> (see below).
1336 Option <literal>recordOpaque</literal> is an alternative
1337 to record - and <literal>record</literal> option (above) is
1338 ignored if recordOpaque is set. This option is only available in
1339 YAZ 3.0.35 and later and is meant to facilitate Updates with
1345 <entry>syntax</entry>
1346 <entry>The record syntax (transfer syntax). Is a string that
1347 is a known record syntax.
1349 <entry>no syntax</entry>
1352 <entry>databaseName</entry>
1353 <entry>Database from connection object</entry>
1354 <entry>Default</entry>
1357 <entry>correlationInfo.note</entry>
1358 <entry>Correlation Info Note (string)</entry>
1362 <entry>correlationInfo.id</entry>
1363 <entry>Correlation Info ID (integer)</entry>
1367 <entry>elementSetName</entry>
1368 <entry>Element Set for Record</entry>
1372 <entry>updateVersion</entry>
1373 <entry>Record Update version which holds one of the values
1374 1, 2 or 3. Each version has a distinct OID:
1376 (<ulink url="&url.z39.50.extupdate1;">first version</ulink>) ,
1378 (second version) and
1379 1.2.840.10003.9.5.1.1
1380 (<ulink url="&url.z39.50.extupdate3;">third and
1381 newest version</ulink>).
1391 <sect2 id="zoom.database.create"><title>Database Create</title>
1393 For Database Create, type must be set to <literal>create</literal> in
1394 <function>ZOOM_package_send</function>.
1397 <table frame="top" id="zoom.database.create.options">
1398 <title>Database Create Options</title>
1400 <colspec colwidth="4*" colname="name"></colspec>
1401 <colspec colwidth="7*" colname="description"></colspec>
1402 <colspec colwidth="3*" colname="default"></colspec>
1405 <entry>Option</entry>
1406 <entry>Description</entry>
1407 <entry>Default</entry>
1412 <entry>databaseName</entry>
1413 <entry>Database from connection object</entry>
1414 <entry>Default</entry>
1421 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1423 For Database Drop, type must be set to <literal>drop</literal> in
1424 <function>ZOOM_package_send</function>.
1427 <table frame="top" id="zoom.database.drop.options">
1428 <title>Database Drop Options</title>
1430 <colspec colwidth="4*" colname="name"></colspec>
1431 <colspec colwidth="7*" colname="description"></colspec>
1432 <colspec colwidth="3*" colname="default"></colspec>
1435 <entry>Option</entry>
1436 <entry>Description</entry>
1437 <entry>Default</entry>
1442 <entry>databaseName</entry>
1443 <entry>Database from connection object</entry>
1444 <entry>Default</entry>
1451 <sect2 id="zoom.commit"><title>Commit Operation</title>
1453 For Commit, type must be set to <literal>commit</literal> in
1454 <function>ZOOM_package_send</function>.
1458 <sect2 id="zoom.extended.services.behavior">
1459 <title>Protocol behavior</title>
1461 All the extended services are Z39.50-only.
1465 The database create, drop and commit services are privately defined
1467 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1474 <sect1 id="zoom.options"><title>Options</title>
1476 Most &zoom; objects provide a way to specify options to change behavior.
1477 From an implementation point of view a set of options is just like
1478 an associative array / hash.
1481 ZOOM_options ZOOM_options_create(void);
1483 ZOOM_options ZOOM_options_create_with_parent(ZOOM_options parent);
1485 void ZOOM_options_destroy(ZOOM_options opt);
1488 const char *ZOOM_options_get(ZOOM_options opt, const char *name);
1490 void ZOOM_options_set(ZOOM_options opt, const char *name,
1494 typedef const char *(*ZOOM_options_callback)
1495 (void *handle, const char *name);
1497 ZOOM_options_callback
1498 ZOOM_options_set_callback(ZOOM_options opt,
1499 ZOOM_options_callback c,
1503 <sect1 id="zoom.events"><title>Events</title>
1505 If you're developing non-blocking applications, you have to deal
1509 int ZOOM_event(int no, ZOOM_connection *cs);
1512 The <function>ZOOM_event</function> executes pending events for
1513 a number of connections. Supply the number of connections in
1514 <literal>no</literal> and an array of connections in
1515 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1516 A pending event could be a sending a search, receiving a response,
1518 When an event has occurred for one of the connections, this function
1519 returns a positive integer <literal>n</literal> denoting that an event
1520 occurred for connection <literal>cs[n-1]</literal>.
1521 When no events are pending for the connections, a value of zero is
1523 To ensure that all outstanding requests are performed call this function
1524 repeatedly until zero is returned.
1527 If <function>ZOOM_event</function> returns and returns non-zero, the
1528 last event that occurred can be expected.
1531 int ZOOM_connection_last_event(ZOOM_connection cs);
1534 <function>ZOOM_connection_last_event</function> returns an event type
1535 (integer) for the last event.
1538 <table frame="top" id="zoom.event.ids">
1539 <title>ZOOM Event IDs</title>
1541 <colspec colwidth="4*" colname="name"></colspec>
1542 <colspec colwidth="7*" colname="description"></colspec>
1545 <entry>Event</entry>
1546 <entry>Description</entry>
1551 <entry>ZOOM_EVENT_NONE</entry>
1552 <entry>No event has occurred</entry>
1555 <entry>ZOOM_EVENT_CONNECT</entry>
1556 <entry>TCP/IP connect has initiated</entry>
1559 <entry>ZOOM_EVENT_SEND_DATA</entry>
1560 <entry>Data has been transmitted (sending)</entry>
1563 <entry>ZOOM_EVENT_RECV_DATA</entry>
1564 <entry>Data has been received)</entry>
1567 <entry>ZOOM_EVENT_TIMEOUT</entry>
1568 <entry>Timeout</entry>
1571 <entry>ZOOM_EVENT_UNKNOWN</entry>
1572 <entry>Unknown event</entry>
1575 <entry>ZOOM_EVENT_SEND_APDU</entry>
1576 <entry>An APDU has been transmitted (sending)</entry>
1579 <entry>ZOOM_EVENT_RECV_APDU</entry>
1580 <entry>An APDU has been received</entry>
1583 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1584 <entry>A result-set record has been received</entry>
1587 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1588 <entry>A search result been received</entry>
1596 <!-- Keep this comment at the end of the file
1601 sgml-minimize-attributes:nil
1602 sgml-always-quote-attributes:t
1605 sgml-parent-document: "yaz.xml"
1606 sgml-local-catalogs: nil
1607 sgml-namecase-general:t